Evaluation of Irrigation Scheduling on Performance of Summer Legumes Grown in Association with Sugarcane

Abstract

The study was carried out in 2017 in order to find an optimum irrigation schedule for performing intercropping in case of sugarcane, with silty clay-loam soil type. The highest yield rate was noted in mung bean (Phaseolus radiatus L.), urad bean (P. mungo L.) and cowpea [Vigna unguiculata (L.) Walp.] that is 4.1, 3.85 and 73.0 q/ha, respectively, with irrigation at 1.2 IW:CPE ratio as compared to 3.25, 2.75 and 6.10 q/ha when irrigation was done at the flowering and pod-filling stage. However, the cane yield was found to be reduced in case of intercropping due to less number of millable canes and weight of the cane. The rate of reduction in case of growing sugarcane with cowpea, urad beans and mung beans was 14.2%, 11.5% and 9.2%, respectively, With irrigation at 1.2 IW:CPE ratio, which led to an increased cane yield of 97.0 tonnes/ha. This value was 3.7%, 8.1% and 13.3% higher than 1.0 and 0.8 IW:CPE ratio along with irrigation at critical growth stages. Highest cane yield and economic return was obtained in case of intercropping with cowpea (107 tonnes/ha; Rs. 101,650/ha)), which was 6.8%, 10%, and 8.7% more as compared to growing only sugarcane (Rs 95,190/ha), sugarcane with urad bean (Rs 92,435), and with mung bean, respectively. The benefit:cost ratio was 0.89, 0.90 and 0.73, respectively. Highest cane yield was observed with irrigation at 1.2 IW:CPE ratio (109.5 tonnes/ha) with benefit:cost ratio of 0.85 as against 92.4 tonnes/ha and 0.77 with irrigation at critical growth stages of intercrops.